Microwave oven cooking continues to increase due to the associated convenience and time savings. The growth in microwave oven usage has been accompanied by a similar growth in the demand for microwaveable prepared foods. Microwave packages are increasingly popular since they allow the food product to be stored and cooked in the same container, further increasing the convenience in microwave cooking. It is known that the configuration and materials in microwave packages can have a substantial effect upon the result of microwave cooking. However, many foods cooked in a microwave do not satisfy the customers' expectations or tastes, since they may lack many of the characteristics which consumers generally associate with such products. In particular, consumers are often dissatisfied with food products which should have a browned and/or crisped surface when properly cooked, since the microwave cooked version may result in a soggy or uncooked exterior. In addition, if cooking of the food product is continued in an attempt to achieve crispness, other portions of the food product may become overcooked.
Numerous attempts have been made to provide microwave cook-in food packages which are adapted to compensate for the lack of food browning or crisping associated with microwave cooking. However, previous attempts have not provided an entirely satisfactory package for cooking edge surfaces of food products such as to provide browning or crispness, particularly where it is desired to package a number of food product articles having surfaces requiring browning or crisping for customer satisfaction.
One approach to providing browning, as disclosed in U.S. Pat. No. 4,267,420 to Brastad and U.S. Pat. No. 4,230,924 to Brastad et al. , includes the use of flexible sheets of microwave interactive materials wrapped closely about food items wherein the interactive material converts at least a portion of the impinging microwave energy into heat for browning the food surface. However, wrapping individual food items increases the cost and complexity associated with packaging the food products. In addition, where a number of food items are packaged together, the consumer may find it cumbersome to remove the wrappings from the food products, particularly when the food product is hot after cooking.
U.S. Pat. Nos. 4,594,492 to Maroszek and 4,794,005 to Swiontek disclose microwave packages in which a microwave interactive layer is provided on interior surfaces of the container. In each of these arrangements, a tray or insert having a microwave interactive layer thereon is provided such that the microwave interactive layer is closely adjacent to the food product, thereby improving browning of the food product portions adjacent the tray or insert. However, the manufacture of separate inserts or trays, and orientation of the inserts within the container complicates packaging. Moreover, these patents do not address the problems associated with cooking a food portion which includes a plurality of food articles, each having surface areas for which crisping and/or browning is desired. For example, in U.S. Pat. No. 4,594,492 to Maroszek, an insert having a microwave interactive layer thereon is biased from the top of the carton towards a food product, such as a plurality of sausage links arranged in a row. However, the majority of the browning occurs at the bottom and top surfaces of the sausage links and such an arrangement would not be suitable for browning side portions of a plurality of articles, since a majority of the article side portions are remote from the microwave interactive layers, and the side surfaces are generally in contact with adjacent food articles.
Particularly where the food articles are of an irregular shape, having side surfaces as large or greater than the top and bottom surfaces, prior art packages have been insufficient in properly cooking the food article side surfaces and at best only brown or crisp the side surfaces of the food articles which are adjacent the container side walls. Where it is desired to package two or more rows of food articles, it becomes increasingly difficult to properly cook the side surface areas since the side surface area of the articles in the center of an array of food articles are remote from the microwave interactive layers associated with the interior surface areas of the package.
Thus, a microwave package is needed which is capable of heating side portions of food articles, particularly where the food articles have large side surfaces and a number of such food articles are packaged and cooked together, for example two or more articles; or two or more rows of food articles.